AND ON THE LAW OF PRESSURE OF GASES, ETC. 
21<) 
Table VI.—Nitrogen. 
November 17-18, Zero = 437. 
Volume in 
cub. centims. 
Pressure in 
scale divisions. 
Log. product. 
Pressure in 
millims. Hg. 
Deviation 
of ])V. 
Error of -p 
in millims. 
V + 40 
11-40 
•989 
•049 
+ -005 
+ -0002 
V + 60 
9-10 
•983 
•039 
- -009 
- -0004 
V + 80 
7-65 
•983 
•033 
- -009 
- -0003 
V +110 
6-25 
•988 
•027 
+ -002 
+ -0001 
V +150 
5-10 
•999 
•022 
+ -028 
+-0006 
V +190 
4-05 
•980 
•017 
- -016 
- -0003 
•987 
Table VII.—Nitrogen. 
November 18-1'J, Zero = 43'8. 
1 
Volume in 
cub. centims. 
Pressure in 
scale divisions. 
Log. product. 
Pi essure in 
millims. Hg. 
Deviation 
of pr. 
Error of p 
ill millims. 
V + 40 
5-90 
• 703 
•02G 
+ -014 
+ -0004 
V + GO 
4-GO 
• G8G 
• 020 
- ■ 02G 
- -0005 
V + 80 
4-15 
•717 
■018 
+ -047 
+ -0008 
V +110 
3-10 
•GS3 
•013 
- -033 
- -0004 
V +150 
2 • 55 
•G98 
•on 
+ -002 
•0000 
• G97 
In the second set the quantity of gas had been adjusted to give a snitalde })ressure 
with V — 0. It is from it and from Tal)le 1. tliat tlie data were oljtained for the 
calculation of V already given. 
These tables give a fairly complete account of the behaviour of nitrogen from a, 
pressure of about 1'5 millims. down to ‘01 millim. of mercury. In each set the range 
of pressure is nearly in the ratio of 3:1, and overlaps the range of the pre¬ 
ceding and following sets. An examination of the fifth column shows no indication 
of departure from Boyle’s law. The sixth column allows a judgment to he formed 
of the degree of accuracy to which the law is verified. It gives the amount by 
which p exceeds the value necessary in order that pv should be absolutely constant, 
expressed in millimetres of mercury. The errors thus exhibited include not only those 
arising in the setting of the manometer and the reading of the telesco})e, hut also 
those entailed in the measurements of volume, and in consequence of fluctuations of 
temperature. The latter source of error is of course more important at the higher 
pressures. It will he seen that the accuracy attained is very remarkal)le. Even at 
the higher pressures the mean error is only about ‘001 millim., while at the lower 
O 1,1 o 
w X' 
